import java.util.List;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 86183
 * Date: 2024-01-05
 * Time: 20:19
 */
public class MySingList implements IList{
    static class ListNode{
        public int val;
        public ListNode next;
        public ListNode(int val) {
            this.val = val;
        }
    }
    public ListNode head;

    @Override
    public void addFirst(int data) {
        ListNode node=new ListNode(data);
        if(head==null){
            head=node;
        }else {
            node.next = head;
            head = node;
        }
    }

    @Override
    public void addLast(int data) {
        ListNode node=new ListNode(data);
        if(head==null){
            head=node;
        }else{
            ListNode cur=this.head;
            while(cur.next!=null){
                cur=cur.next;
            }
            cur.next=node;
        }

    }

    @Override
    public void addIndex(int index, int data) {
        if(index<0||index>size()) {
            System.out.println("插入位置错误:" + index);
            return;
        }
        if(index==0){
            addFirst(data);
            return;
        }
        if(index==size()){
            addLast(data);
            return;
        }
        ListNode cur=findAddIndex(index);
        ListNode node=new ListNode(data);
        node.next=cur.next;
        cur.next=node;

    }
    private ListNode findAddIndex(int index){
        ListNode cur=this.head;
        while(index-1!=0){
            index--;
            cur=cur.next;
        }
        return cur;
    }

    @Override
    public boolean contains(int key) {
        ListNode cur=this.head;
        while(cur!=null){
            if(cur.val==key){
                return true;
            }
            cur=cur.next;
        }
        return false;
    }

    @Override
    public void remove(int key) {
        if(head.val==key){
            head=head.next;
            return;
        }
        if(isEmpty()){
            System.out.println("单链表为空");
            return;
        }
        ListNode cur=findRemove(key);
        if(cur==null){
            System.out.println("未找到该元素，无法删除");
            return;
        }
        cur.next=cur.next.next;
    }
    public boolean isEmpty(){
        if(size()==0){
            return true;
        }
        return false;
    }
    private ListNode findRemove(int key){
        ListNode cur=this.head;
        while(cur.next!=null){
            if(cur.next.val==key){
                return cur;
            }
            cur=cur.next;
        }
        return null;
    }
    @Override
    public void removeAllKey(int key) {
        if(head==null){
            return;
        }
        ListNode cur=head.next;
        ListNode pre=head;
        while(cur!=null){
            if(cur.val==key){
                pre.next=cur.next;
                cur=cur.next;
            }else{
                pre=cur;
                cur=cur.next;
            }
            if(head.val==key){
                head=head.next;
            }
        }


    }

    @Override
    public int size() {
        ListNode cur=this.head;
        int count=0;
        while(cur!=null){
           count++;
            cur=cur.next;
        }
        return count;
    }

    @Override
    public void display() {
        ListNode cur=this.head;
        while(cur!=null){
            System.out.print(cur.val+" ");
            cur=cur.next;
        }
        System.out.println();
    }

    @Override
    public void clear() {
        ListNode cur=head;
        while(cur!=null){
            ListNode cur2=cur.next;
            cur.next=null;
            cur=cur2;
        }
        head=null;
    }

}
